Activities:

Based on John Valley Scientific American Paper [Valley, 2005] . All students read article. One student presents. One week before presentation they must hand out 10 questions that students must answer and come to class with them answered so that they can be prepared for discussion.

Goals:

Example

Here is an example of a literature-based assignment using this topic, submitted by Dr. Lindy Elkins-Stanton, Massachusetts Institute of Technology.
Scientific Paper Reading: Continental Growth(Microsoft Word 42kB Jul17 07) The file includes the reading list used in an introductory course for earth science majors.

2. Introductory Level - Jigsaw

Content:

Different hypotheses for crustal growth- rapid vs. slow growth rates—can discuss before (intro, major) or after jigsaw group (non-major, intro)

Data:

Three graphs or papers

Rapid burst growth graph

Episodic

Gradual

Process:

First, expert groups for each graph or paper

Second, mixed group and explain their data to each other and form questions about their data discussion

Third, groups present their findings

What conclusion did they get from their discussion?

How did they weight the data to get to their conclusion?

What would you do next?

Fourth, now instructor can compare their conclusions with recent hypotheses that scientists are working on.

Get paper references:

Richard Armstrong—review paper: crustal growth curves

John Valley—oxygen isotope

Taylor, Scott McClellan—crustal growth curve paper

Steven Parman—helium papers

Follow-up (major courses)—go back to specialty group and find out about methods.

Have students go find out about methods used in papers above.

Demonstrate relevance: look at curves, crustal growth, of present day and make predictions about future development of shallow water platforms necessary for evolution of atmosphere and life.

Impact Craters

Key questions:

What were the differences between the magma ocean on the Earth and Moon?

Goals and objectives

Clarification of gaps in knowledge such as atmosphere, ocean what surface was like.
Looking at the surface of moon can give analogy of early Earth surface.

Activities:

Begin with pictures of volcanic craters and compare with impact craters.
Create model craters in flour by dropping marbles. Take measurements of height of drop, size and depth of crater, and ejecta.
View clip from "Deep Impact"

Jigsaw

Group #1 ages of rocks on moon and Earth
Group#2 composition of Earth and moon
Group#3 morphology of craters on moon and Earth
Group#4 morphology of craters on Earth
Reassemble to answer question: How did impacts affect early Earth?

How did the Earth form through accretion, and how is this process related to the age of the Earth?

I. Problem: Age dating is a fundamental method of finding the age of earth materials.

However, we can only sample the shallowest portion of the Earth rx (<200km?).

How can we find the age of the Earth?

Background and Context:

Explain nebular hypothesis

Planets grow by accretion of "space stuff."

Exercise - Meteorite age data set

Graph age frequency versus age.

Can be done with "clean" data set by hand or Excel; or can introduce complexity with "dirty" data set.

Group Thinking activity

Interpret the graph

What is the connection between these meteorite dates and our estimate for the age of the Earth?

Learning

Method of age-dating Earth

Reason for age of Earth

II Problem: Given the heat production curve of the Earth, what are the components that contribute? A) kinetic energy from impact to heat, b) Radionuclides c) potential energy liberated due to sinking of dense (Fe) material to the core

Background and Context:

Explain availability of heat available to do work in Early Earth system (melting, differentiation)

Compare with Kelvin's early calculations of heat production and age of earth

Contribution of "extinct" isotopes

Review heat available to do work throughout Earth history - magma ocean, formation of continents, why no Precambrian blueschists?

Project to the future - when will plate tectonics shut down?

Activities

Back of envelope calculation of kinetic energy transferred to heat during impact; bolide of certain mass, moving at velocity, what energy is liberated; how much melt can be generated (latent heat of melting). Different sizes of planetismals – what work will be done for different conditions.

Practice in making graph–show contributions of various heat sources to construct heat curves.

Comparative planetology - what are the heat production curves from Venus and Mars? Discuss and reach an understanding of how those curves were produced. Consider factors such as planetary size/mass, composition, and volatiles.

How did the Earth form?

Course:

Historical Geology (undergrad), especially for large lecture classes

Activities:

Discuss the history of hypotheses regarding the formation of the Earth; show how the discarding of old hypotheses does not mean that nothing is known, merely that new hypotheses need to be created from existing data (i.e., show how science progresses)

Exploring the significance of the Jack Hills zircons

Use "Ripley's Believe It or Not" or other popular article as a launching point

Show images of the Jack Hills location, other pics of Australia; relative sizes of zircons, pennies, etc. to make it "real" to students (zircon images)

Give students Scientific American article on zircons [Valley, 2005] to read

Provenance: Sean Fox, Carleton CollegeReuse: This item is offered under a Creative Commons Attribution-NonCommercial-ShareAlike license http://creativecommons.org/licenses/by-nc-sa/3.0/ You may reuse this item for non-commercial purposes as long as you provide attribution and offer any derivative works under a similar license.

Provenance: GSAReuse: If you wish to use this item outside this site in ways that exceed fair use (see http://fairuse.stanford.edu/) you must seek permission from its creator.

GSA supports On the Cutting Edge

The mission of The Geological Society of America is to advance geoscience research and discovery, service to society, stewardship of Earth, and the geosciences profession. We support geoscience education at every level. Join us at http://www.geosociety.org/

Provenance: NAGTReuse: This item is offered under a Creative Commons Attribution-NonCommercial-ShareAlike license http://creativecommons.org/licenses/by-nc-sa/3.0/ You may reuse this item for non-commercial purposes as long as you provide attribution and offer any derivative works under a similar license.

Value this site? Help us ensure its future.

The On the Cutting Edge website and workshop program are supported by the National Association of Geoscience Teachers (NAGT). Join today and your membership will help ensure that this site can continue to serve geoscience educators. Join NAGT today

Provenance: NAGTReuse: This item is offered under a Creative Commons Attribution-NonCommercial-ShareAlike license http://creativecommons.org/licenses/by-nc-sa/3.0/ You may reuse this item for non-commercial purposes as long as you provide attribution and offer any derivative works under a similar license.

Your NAGT membership helps make this site
possible. Thank you!

The On the Cutting Edge website and workshop program are supported by the National Association of Geoscience Teachers (NAGT). Your membership is helping to ensure that this site can continue to serve geoscience educators.